Background/Purpose: Herpes zoster is a common condition that causes significant pain and, often, post-herpetic neuralgia. In the United States the incidence of zoster per 1,000 person-years is 6 for people 60 years old and increases with age to nearly 11 for people above 80 years old. The incidence of zoster may be increased in autoimmune diseases, but few studies have looked specifically at cutaneous autoimmune diseases. Prior studies have found that the incidence of zoster in systemic lupus erythematosus is up to 32.5 per 1,000 person-years (n=303).

Methods: This retrospective chart review examined the incidence of zoster in patients with cutaneous lupus erythematosus (CLE) (n=105), dermatomyositis (DM) (n=66) and pemphigus vulgaris (PV) (n=55) seen in the practices of two dermatologists between April 1, 2013 and September 31, 2013. An incidence of zoster was determined according to a matched text search for “zoster” or “shingles” in all available electronic medical records. The date of the zoster episode, if known, and the medications that the patient was taking at the time of the episode were recorded. The date of each patient’s earliest visit with his dermatologist recorded in the electronic medical record until the most recent visit through September 31, 2013 or an episode of zoster, whichever was earlier, was used to estimate the time that the person had been at risk. The total number of incidences of zoster divided by the total number of person-years at risk was used to determine the incidence rate. Patients with a known history of zoster prior to the start of their electronic medical records and patients whose date of zoster was unknown were excluded from the incidence rate calculations.

Results: The incidence rate of zoster per 1,000 person-years was 23 for CLE, 54 for DM, and 7 for PV. The incidence rates were based on 6 episodes of zoster per 257.9 person-years for CLE, 8 episodes of zoster per 149.5 person-years for DM and 1 episode of zoster per 145.4 person-years for PV. Six CLE, 7 DM and 3 PV subjects had an unknown date of zoster. One CLE, 5 DM and 2 PV patients had zoster prior to the start of their electronic medical records. The mean (SD) duration of follow-up was 2.7 (1.7) years for CLE, 2.8 (1.7) years for DM and 3.0 (1.8) years for PV. The mean age (standard deviation) of each group was: 46.2 (14.1) for CLE, 55.9 (14.2) for DM and 56.1 (13.8) for PV. Fourteen of the 16 patients who had zoster were on immunosuppressive medications at the time of the zoster episode. Some patients were on more than one immunosuppressive therapy at the time of their zoster episode. The immunosuppressive medications were: mycophenolate mofetil (n=7), prednisone (n=6), methotrexate (n=1) and azathioprine (n=1). The majority of patients in each disease group were Caucasian women.

Conclusion: The incidence rate of zoster in CLE and DM is higher than in the average U.S. population at or above 80 years old. The incidence of zoster in PV is close to that of the average U.S. population of a similar age. The use of immunosuppressive therapies may play a role in the increased incidence of zoster in CLE and DM.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-incidence-of-zoster-in-patients-with-cutaneous-lupus-erythematosus-and-dermatomyositis-is-increased-compared-to-the-average-u-s-population/